Strange Oil Level F150TXR

First time post and I have an F150TXR and I store the boat in the garage. I keep the motor level so I can have room to get around it. I check the oil before pulling it out and I check it after the 15 minute flush after each use.
Well, last weekend, I checked the oil level and the stick was bone dry. This is not the first time the stick has come out dry, either. I Clean and check again and the oil level was 1/2" above the full mark. It usually stays about 1/4" below the full mark. I checked it a few more times and it read the same thing. What's up with that?
In the water I went ahead and started the motor and let it idol until operating temperature and then checked it again. It was still above the full mart but lower than it was cold. I ran it an hour or so and once back at the house I checked it again and it was below full but still higher than normal.
Any Ideas? Any danger?

What happens with some of the 4 stroke outboards is that condensation/water build-up builds up inside the engine and sort of combines with the oil. The reason 2 strokes don't have this problem is because oil does not stay in the crankcase for extended periods of time. Yamaha had sent out some service bulletin a while back, saying that because outboards are so close to water, this condensation doesn't evaporate, or something like that.

Anyways, that is why your oil level is sort of increasing, because there is a little water in it. For a 4 stroke outboard, this is normal so I wouldn't worry too much about it, just stay on top of your oil changes and if you get a LOT of water in there, I would do an oil change. When you look at the oil, sometimes you can see the water which makes sort of a milky-look.

Your only suppose to fill oil to 2/3 thirds in checkered area.

No water in the oil but it does have a gas smell.
There is a long story behind this motor. I bought this boat new in August. It came with an F150TXR built in 2005. Five weeks into ownership and 15 hours in service the motor blew up. Yamaha replaced the powerhead under warranty. I can't seem to keep this thing out of the shop. I wish I could just give it back.

Ive seen a few f150s before and the sometimes the thermostat is stuck open & not coming up to proper operating temp.This causes gas to pass by rings into crankcase.Just check the thermostat.Also the last f150 i worked on we installed a 71 deg. suzuki thermostat to run the motor hotter.still waiting for customers reply

[Woodnaut]

Reata, I have a 4-stroke 90 hp that started "making oil" earlier this year. The term "making oil" refers to the condition of an increase in oil level in the crankcase. For example, a leaking head gasget can cause water to get into the crankcase. In this situation, the oil is visibly discolored and might appear white or "milky".

Gasoline can also enter the crankcase and mix with the oil. Blowby (around the piston rings), a leaking fuel pump diaphragm, or in some cases vapor canister/breather hoses can cause this to occur. The oil viscosity will drop, and it will reek of gas. Im my case, a Yamaha Technician seems to have nailed the cause of my problem - my engine was overpropped. This causes the engine to work harder and therefore increases blowby. Increased blowby can "carbon up" the rings which adds to the problem. I changed back to my original prop (which increased engine RPM and decreased load) and used some Mercury Marine "Power Tune" (to reduce/eliminate carbon on the rings). This seems to have solved the problem. Hope this helps - Woodnaut